3-Pentenoic acid is a well-known intermediate which can be used to make both caprolactam for nylon 6 and adipic acid for nylon 6,6.
The use of cobalt to catalyze the conversion of butadiene to 3-pentenoic acid is known. This reaction requires the presence of a base, such as pyridine, and relatively high pressures, e.g., 3,000 to 10,000 psig and temperatures, e.g., 130.degree. C. to 160.degree. C. See U.S. Pat. Nos. 4,925,972 and 4,894,474.
The use of rhodium and palladium to catalyze the conversion of butadiene to 3-pentenoic acid is also known. See U.S. Pat. Nos. 5,494,041; 5,250,726; 5,145,995 and 5,672,732. The use of these metals suffers from the disadvantages of the high cost of the metals and the use of relatively high temperatures, i.e., above 140.degree. C.